When Cambodia spoke about the border dispute, however, Thai Foreign Minister Kasit Promya, visibly irked, said he was ready to argue with anyone who would attempt to discuss the bilateral conflict in detail during the annual gathering. After the outburst, the other ministers evaded the issue, according to two ASEAN diplomats who attended the meeting and spoke on condition of anonymity because of the sensitivity of the dispute.

As current chair of ASEAN, Indonesia has been trying to help mediate the dispute over small parcels of land claimed by both countries, but has so far made little headway.

Cambodian Prime Minister Hun Sen said he wants ASEAN to oversee a permanent cease-fire, according to his top adviser, Sri Thamrong, but Thailand still believes the problem should be settled bilaterally or through the International Court of Justice.

Philippine Foreign Secretary Albert del Rosario told reporters that during the ministerial meeting, he raised the need for ASEAN to end a nine-year disagreement with China that has prevented both sides from completing the guidelines of a 2002 accord aimed at preventing armed conflicts over the disputed Spratly Islands.

The guidelines would allow China and claimant countries to pursue joint development projects to ease tensions in the disputed South China Sea region, he said.

Four ASEAN members - Brunei, Malaysia, the Philippines and Vietnam - are among the claimants. They have agreed to pursue their claim as a bloc through ASEAN, but China has disagreed, preferring to discuss the dispute bilaterally.

Meanwhile, Myanmar's president, Thein Sein, who heads the military-backed party that overwhelmingly won general elections late last year, was expected to ask for the right to chair ASEAN in 2014.

The regional grouping is supposed to rotate its chair every year between member countries - Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Singapore, Thailand and Vietnam.

However, Myanmar was forced to skip its turn in 2005 after coming under heavy pressure from the international community over slow progress on national reconciliation and human rights.

Thailand and several other countries have indicated they wouldn't be opposed to Myanmar chairing ASEAN in 2014, but Singapore said it would be better to push back the date because of lingering concerns about human rights abuses.